Binary Large OBject (BLOB) format is used to store image, audio, video directly into database and not into a file system and then saving the location in the database.
To store an image in database you can directly use Imagic library to convert the image into BLOB
<?php
$imagick = new Imagick();
//Your image file
$image = dirname(__DIR__) . "/example/images/github_logo.png";
$image_file = fopen($image, "a+");
$imagick->readImageFile($image_file);
//if not applied utf-8 encode it throws decoding error output not utf-8
$image_blob = utf8_encode($imagick->getImagesBlob());
var_dump($image_blob);